The assignee of the present invention manufactures and deploys spacecraft for, commercial, defense and scientific missions. On board propulsion systems of such spacecraft are frequently required to perform orbit raising (or transfer). For example, there is frequently a requirement for commercial spacecraft to perform orbit raising from a launch vehicle transfer orbit (or “parking orbit”) to, for example, a geosynchronous orbit. Following separation from the launch vehicle, the spacecraft then performs transfer orbit operations to transfer the spacecraft from the parking orbit to the geosynchronous orbit. The transfer orbit operations conventionally include firing a liquid apogee motor (LAM) and/or firing low thrust electric thrusters. After the spacecraft has completed its transfer orbit, the spacecraft may be reconfigured into an “on-orbit” three axis stabilized configuration.
Transfer orbit operations following launch vehicle separation typically include initial spin up about a spin axis, LAM and/or electric thruster firings, coast periods, spin rate changes, and reorientation of the spin axis during and between firings
Alternatively, orbit raising operations may be conducted in a three-axis stabilized configuration, but such transfer orbit operations entail accumulation of momentum in reaction wheels, and periodic offloading, (or “dumping”) of the momentum by thruster firings during and between LAM firings. The above mentioned operations of changing the satellite spin rate, dumping momentum, and reorienting a spinning satellite consume, undesirably, an appreciable amount of propellant